When Brad Adams wrote ASP.NET MVC Example Application over Northwind with the Entity Framework, in respect to data, he stated:
Next, we need to create a LINQ model on top of northwind to make it easier to work with... You can do this with NHibernate, LinqToSql, Entity Framework , or any other .NET OR-Mapping technology. As long as it results in .NET Object, the ASP.NET MVC framework can work with it. In this case I am going to use the Entity Framework.
Interesting choice, NHibernate. This seems to be an endorsement, what do you think? More, SubSonic is not on the list, oops...
And then again it probably doesn't mean anything else but the openness of mind Microsoft is breathing right now.